I've been working on some old film scans that have all been converted to photoshop. Ideally when editing these images I go back into photoshop. However, at times I find that I just need a quick adjustment in lightroom. Is there anything wrong with doing it this way? Or should what was started in photoshop stay in photoshop?

I don't know about "should," but I often handle scans this way. Lightroom does a nice job with TIFF files from my scanner, and it lets me organize them with my digital camera files. Since LR doesn't change any of the underlying pixels, I can't see how using it could be a bad thing.

Ken is correct. I prefer to do most of my editing of my film scans in LR (or ACR), with some PS edits, too. Either approach is fine. For more info on this topic, maybe more than you’ll want, here are two recent threads:

Nothing wrong with using LR only to edit scans. Keep in mind though that if you work on an image in LR then want to go back to PS, the LR edits won't automatically be visible. You have to render out a new image to get the LR edits to carry through to PS.

Or from LR, open in PS as a Smart Object, so you can go back and forth between LR and PS to tweak your edits.

Can you expand on this?

If I open an image from LR as an SO in PS, any additional changes I make in LR are not reflected in the SO because I'm working on a copy of the original in the SO. I can double click to open the copy in ACR and make changes but those changes won't be reflected in the original in LR. When that image is saved, it will be saved as a second image in LR.

If I open an image from LR as an SO in PS, any additional changes I make in LR are not reflected in the SO because I'm working on a copy of the original in the SO. I can double click to open the copy in ACR and make changes but those changes won't be reflected in the original in LR. When that image is saved, it will be saved as a second image in LR.

When using smart objects, you can decide to re-edit the SO from within PS, which will then open the SO in Adobe Camera Raw. There in ACR, you can edit the original raw file and changes saved will then appear back in SO file in PS.

You could use snapshots to save changes made in ACR. Just update file from within LR.

No, you're not working on the original with an SO. You're working on a copy of the original. If you open a file from LR into PS, edit then save it, whatever edits you've made in PS or ACR will be saved to a new file. The original won't be overwritten. You're always going to create a new file if you choose to open the file from LR. If you open it directly from PS or ACR then you'll overwrite the original.

You don't even need snapshots in ACR to have the original updated in LR. Any change you make in ACR will write out an xmp file, or update an existing xmp file, and the image will show a metadata conflict in LR. Resolving that conflict will update the image with the latest settings made in ACR. Just as using CTRL+S (or the Mac equivalent) in LR will update the XMP file and if the file is then opened directly in ACR, those changes will be visible.

That's working with a file directly in ACR/LR; however. It's not opening a file from LR into PS, whether as an SO or not. In that case you're always creating a duplicate file.

You don't even need snapshots in ACR to have the original updated in LR. Any change you make in ACR will write out an xmp file, or update an existing xmp file, and the image will show a metadata conflict in LR. Resolving that conflict will update the image with the latest settings made in ACR. Just as using CTRL+S (or the Mac equivalent) in LR will update the XMP file and if the file is then opened directly in ACR, those changes will be visible.

If you open a file from LR as a smart object in PS, PS is no longer referencing the original file, but a copy of that file that is in the photoshop document. Any ACR edits of the smart object while in Photoshop do not reference back to the xmp for the original file, and you do not see a metadata conflict in LR.

Yes, correct, when you open a photo from LR into PS as a SO, that SO is a copy of the LR original and further edits to that SO are then made in ACR (not LR as I stated earlier). Here is a good tutorial:

If you want to want to work with a SO from LR in PS, your versions of LR and PS need to be compatible. If you use LR4, you’ll need PS6. (Although I’m not sure if you use LR4 but Process 2010.) If you use an earlier version of LR, then you can use an earlier version of PS.

If you want the benefits of a SO, use LR4, but have an older version of PS, you can do so generally with a little work around. From LR, open your photo in PS with your LR edits (it will be a copy, not your original). In PS work with layers. If you later decide you want to make some changes to your “background” layer, open LR, edit the original photo, and then open it in PS with your LR edits (again it will be a copy). Then, drag this new version onto your layered PS file to just above the background layer. You can then delete your background layer (and rename the new layer “background”).

The only "problem" with SO's is that you now embed the raw (at that stage) into the Photoshop doc, LR is unaware of what you do from this point. You've spun off another raw iteration. Of course, this only works well when Photoshop and LR are on version parity. If you had say LR4 but PS CS5, you're out of sync and the SO processing can't match the initial LR processing. So for this to work well, it's useful when ACR and LR are on version parity.

The other thing to keep in mind is that the raw is embedded into the PS document, making it larger (you know have two raw files, one in PS, one in LR).

IF you do the LR processing to it's final steps, then render and move into Photoshop, this is all moot.

You can use Lightroom to edit your Photoshop Smart Objects instead of ACR. Make the edits in LR, then in PS replace the contents of the smart object with the LR-edited version (Layer / Smart Objects / Replace contents).

I picked up this hint from Julieanne Kost, Adobe evangelist. Kudos to her.

I believe that only works with RAW images. I don't believe it works with TIFF or JPEG. The xmp file will be read with the updated LR adjustments to a RAW file. But you have to fully render out the TIFF or JPEG for LR adjustments to be applied in the case of those files, I believe. In the case of what the OP is asking he wouldn't be working with camera RAW files after scanning. Even in the case of RAW files, the replacement doesn't happen directly, it still opens the file in ACR. There's really no difference or benefit, except maybe the metadata conflict.

You can use Lightroom to edit your Photoshop Smart Objects instead of ACR. Make the edits in LR, then in PS replace the contents of the smart object with the LR-edited version (Layer / Smart Objects / Replace contents).

Why then embed it as a SO? Seems like you lose the flexibility in just doing a quick tweak in ACR.

Why then embed it as a SO? Seems like you lose the flexibility in just doing a quick tweak in ACR.

Sure, all a matter of personal preference and situation dependent. It's an option some may find attractive, especially if you prefer using LR vs ACR and cataloguing your raw masters in LR. Drop into ACR for a quick tweak before a weblog post? Sure. Do the same for your limited-edition portfolio masters? Maybe not.